An official website of the United States government
Here’s how you know
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
El Nino; atmospheric precipitation; cold season; drought; growth rings; models; spectral analysis; variance; winter; Colorado; New Mexico
Abstract:
... A 1000-year reconstruction of winter (cool season) November-May precipitation for northern New Mexico is developed for AD 985-1970 based on six millenium-long tree-ring records from moisture-sensitive coniferous sites in New Mexico and southern Colorado. Two of the most prolonged and severe droughts occurred during the last 100 years: in the AD 1890s-1904 and the AD 1950s-early 1960s. These were e ...
Pinus ponderosa; canopy; climate; coniferous forests; fire frequency; fire history; fire regime; fire scars; fire severity; fires; fuels; growth rings; models; plateaus; protocols; regression analysis; trees; Arizona; New Mexico
Abstract:
... Fire history reconstructions from fire scars in tree rings have been valuable for assessing fire regime changes and their climatic controls. It has been asserted, however, that these two- to four-century long records from the western USA are unrepresentative of longer periods of the Holocene and are of limited use for understanding current or future fire regimes. The Medieval Climate Anomaly (800– ...
cotton; organic production; Zea mays; heat treatment; harvesting equipment; fiber quality; insect pests; pest control; California; New Mexico; Texas
Abstract:
... Organic cotton production requires alternatives to havest aid chemicals for crop termination and fiber quality preservation. In these trials, a self-propelled two-row thermal defoliation apparatus was tested in spindle picked and stripper harvested cotton. HVI classing data for thermal, chemical, and untreated control plots were compared. Fiber property data from similar trials in 2002 were presen ...
Acer; Curculionidae; Dendroctonus rufipennis; Picea; funnel traps; kairomones; probability; repellents; stand characteristics; trees; New Mexico; Rocky Mountain region; Utah
Abstract:
... We tested 3-methylcyclohex-2-en-1-one (MCH) and an Acer kairomone blend (AKB) as repellent semiochemicals for area and single tree protection to prevent spruce beetle (Dendroctonus rufipennis Kirby) attacks at locations in Utah and New Mexico. In the area protection study, we compared host infestation rates of MCH applications at three densities (20, 40, and 80 g MCH ha–¹) against a control treatm ...
Juniperus monosperma; Pinus edulis; models; pinyon-juniper; roots; soil depth; soil water; soil water content; time series analysis; trees; woodlands; New Mexico
Abstract:
... AIMS: (1) To develop a 3D root distribution model for piñon-juniper woodland using only tree species, sizes and locations as input. (2) To interpret a two-year time series of soil moisture relative to root distributions. METHODS: The study was conducted in a piñon (Pinus edulis (Englem.)) -juniper (Juniperus monosperma (Englem.) Sarg.) woodland in New Mexico. We extracted roots from 720 soil block ...
Bayesian theory; El Nino; Holocene epoch; Pinus edulis; Pinus ponderosa; Zea mays; carbon; climate; corn; drought; ecosystems; humans; introduced species; linear models; oxygen; palynology; pinyon-juniper; plateaus; pollen; pollen analysis; radionuclides; stable isotopes; territoriality; trees; woodlands; Central America; New Mexico
Abstract:
... Pollen analysis is frequently used to build climate and environmental histories. A distinct Holocene pollen series exists for Chaco Canyon, New Mexico. This study reports linear modeling and hypothesis testing of long distance dispersal pollen from radiocarbon-dated packrat middens which reveal strong relationships between piñon pine (Pinus edulis) and ponderosa pine (Pinus ponderosa). Ponderosa p ...
germplasm; cultivars; Medicago sativa; genotype; computer software; databases; New Mexico
Abstract:
... Due to modern plant breeding methods, agricultural producers have many cultivars available for many different species. Consequently, it is often difficult to recommend a cultivar for a particular growing area. A list of alfalfa cultivars, germplasms, and breeding lines available was published. However, due to the large number of entries in these publications finding pertinent information about a c ...
... APEX (Agricultural Policy/Environmental eXtender) is an oft-used agroecosystem model but has limited use in groundwater-driven watersheds due to a simplistic representation of groundwater processes. This paper presents the linkage of APEX and the groundwater flow model MODFLOW into a single modeling code. The mapping of recharge, groundwater head, and groundwater-surface water interactions are han ...
Amorpha nana; Tetraneuris; canyons; data collection; dust; herbaria; morphometry; phylogeny; species diversity; statistical analysis; storms; watersheds; Chihuahuan Desert; Colorado; Comanche National Grassland; New Mexico; Rocky Mountain region
Abstract:
... Despite a dearth of biological study in the area, the Purgatory Watershed concentrated in southeastern Colorado and northeastern New Mexico is home to a number of unique land formations and endemic organisms. At onetime nonarable land where Dust Bowl storms of the 1930s originated, the Purgatory Watershed is presently home to the Comanche National Grasslands, the Picketwire Canyonlands, and the ex ...
... Environmental gradients are expected to alter the relative effects of host-plants and natural enemies on phytophagous insects. Moreover, studies of gradients may assist in an identification of the factors important to the outcomes of trophic interactions. We investigated the role of elevation-based variation in environmental conditions (temperature and relative humidity) and foliar nitrogen on tri ...
biomass; community structure; ecosystems; grasslands; nitrogen; nitrogen fertilizers; plant communities; prescribed burning; primary productivity; root growth; seasonal variation; soil chemistry; soil ecology; soil fertility; species diversity; summer; water stress; Chihuahuan Desert; New Mexico
Abstract:
... Increased available soil nitrogen can increase biomass, lower species richness, alter soil chemistry and modify community structure in herbaceous ecosystems worldwide. Although increased nitrogen availability typically increases aboveground production and decreases species richness in mesic systems, the impacts of nitrogen additions on semiarid ecosystems remain unclear. To determine how a semiari ...
interspecific variation; arid zones; grasses; long term experiments; shrubs; plant litter; carbon nitrogen ratio; biodegradation; chemical constituents of plants; lignin; habitats; New Mexico
deserts; grasslands; shrublands; annuals; plant communities; primary productivity; species diversity; rain; temporal variation; New Mexico
Abstract:
... Precipitation variability and shrub encroachment in response to global environmental change are likely to affect both richness and aboveground net primary production (ANPP) of annual plants in arid and semi-arid ecosystems in the northern Chihuahuan Desert, especially given the grazing history and desertification potential of this aridland region. Using a nine-year dataset (1999–2007), we examined ...
Bufo; rivers; stream flow; reproductive behavior; semiarid zones; riparian areas; floodplains; flooded conditions; population size; groundwater; frogs; New Mexico; Rio Grande River
Abstract:
... Abundance and size of toads (Bufo woodhousii and B. cognatus) were related to precipitation, river flow, and groundwater over 7 years along the Middle Rio Grande, a regulated river in the semi-arid southwestern United States. Toads were monitored in riparian areas at 12 sites spanning 140 km of river during summers 2000-2006. Regional precipitation varied between years, with occurrence of both dro ...
... Developed waters may improve arid landscapes for birds, but their efficacy requires further study. I counted birds along five 300-m transects originating at point sources of water in a New Mexico grassland, and compared results with those from transects without water. Total birds were nearly three times more abundant on transects with water, but differences were greater in spring and winter than d ...
... Thinning, mastication, and prescribed fire are restoration treatments frequently employed in unnaturally dense second-growth Pinus ponderosa forests of the Western United States. Although a goal of these treatments is to restore ecosystem structure and function, little information is available regarding treatment effects on soil micro- and mesofauna, which comprise the overwhelming majority of met ...
Acarospora; California; Chihuahuan Desert; Mexico; New Mexico; South America
Abstract:
... Eighteen described Acarosporaceae are reported from the Chihuahuan Desert in southern New Mexico. Ten species reported by Magnusson from northern New Mexico were collected in the Chihuahuan Desert. Four species described by Magnusson are revised and taken out of synonymy: Acarospora amabilis, A. applanata, A. carnegiei and A. tenebrica. The squamulose yellow species A. organensis, new for science, ...
Baldwin, Laura-Mae; Hollow, Walter B.; Casey, Susan; Hart, L. Gary; Larson, Eric H.; Moore, Kelly; Lewis, Ervin; Andrilla, C. Holly A.; Grossman, David C.
American Indians; rural health clinics; rural health care; health care workers; surveys; statistics; Montana; New Mexico
Abstract:
... Context:The Indian Health Service (IHS), whose per capita expenditure for American Indian and Alaska Native (AI/AN) health services is about half that of the US civilian population, is the only source of health care funding for many rural AI/ANs. Specialty services, largely funded through contracts with outside practitioners, may be limited by low IHS funding levels. Purpose: To examine specialty ...
Antilocapra americana; ecosystems; grasslands; pastures; plant communities; population size; rangelands; walking; Chihuahuan Desert; New Mexico
Abstract:
... Two techniques frequently used for monitoring pronghorn populations were compared in vegetation communities of the Chihuahuan Desert in New Mexico, USA. The evaluated techniques included the walking line transect and the driving line transect under two vegetation types and relative to season. The true population value (control) used to evaluate the techniques was a complete census using flights co ...
altitude; climate change; climate models; decision making; hydrologic data; irrigation; remote sensing; runoff; snow; snowmelt; temperature; water shortages; New Mexico
Abstract:
... Traditional forms of acequia irrigation can be combined with ground based and remote sensing snow measurements and snowmelt runoff modeling to better estimate runoff volumes now and in the future under conditions of climate change. The experience gained over 400 years of irrigating small fields strongly binds communities and strengthens the resolve of acequia associations to contest challenges pre ...